FEASIBILITY STUDY ON THE UTILIZATION OF PARACHUTE DROGUES AND SHORE-BASED RADAR TO INVESTIGATE SURFACE CIRCULATION IN MONTEREY BAY by Howard Sanford Stoddard United States Naval Postgraduate School rn rHESI FEASIBILITY STUDY ON THE UTILIZATION OF PARACHUTE DROGUES AND SHORE-BASED RADAR TO INVESTIGATE SURFACE CIRCULATION IN MONTEREY BAY by Howard Sanford Stoddard Thesis Advisor: W. W. Denner March 1971 Approved ^on. pub tic. Sidzoi a; ctibtnA.bmU.on untimltzd. T 1001 Feasibility Study on the Utilization of Farachute Drogues and Shore-Based Radar to Investigate Surface Circulation in Monterey Bay by Howard Sanford, Stoddard Lieutenant Commander, United States Navy B.S., United States Naval Academy, 1963 Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN OCEANOGRAPHY from the NAVAL POSTGRADUATE SCHOOL March 1971 S?3« «**rm cnuri Figure 3. Monterey Bay * NAVAL POSTGRADUATE SCHOOL 14 major offshore oceanic current system is the California Current, which comprises the easterly leg of the general North Pacific clockwise gyre. The location of its southerly flow relative to the California coastline will vary depending on the season. During certain months of the year, another current predominates along the California coast. This is the Davidson Current, with a general northerly drift. Skogsberg [1936], in a hydrographic survey of Monterey Bay, described the water structure of the Bay by dividing it into three seasonal phases related to the existing thermal conditions: (1) an upwelling period from mid-February to late August, (2) an oceanic period from late August to late October and (3) a Davidson Current period from mid-November to mid-February. The upwelling phase was characterized by an upsurge of deep cold waters into the coastal region. The oceanic phase was distin- guished by a sharp diminishment in the upwelling and a shift in flow of the California Current in toward the coastline. The Davidson Current was characterized by a northerly current flow during the winter months. The prevailing wind conditions for the area tend to correspond with the direction of the oceanic current flow. During the winter months, when the Davidson Current predominates, the prevalent winds are from the south or southwest. During the balance of the year, when the southerly flowing California Current predominates, the winds blow normally out of the north or northwest. The tidal cycle plays an important contributing role in the surface circulation in Monterey Bay. The tides generally exhibit a semidiurnal inequality. The tides have a mean range of 1.16 m, and a mean diurnal range of 1 .68 m. 15 C. PREVIOUS CURRENT STUDIES OF MONTEREY BAY The first detailed discussion of currents in Monterey Bay was done by Skogsberg [1936]. He analyzed thermal structure data collected in the Bay over a five year period (1929-1933) to determine circulation patterns. In conjunction with this research, he utilized a type of free-floating drogue to study the effects of tidal variation upon Bay currents off of the Hopkins Marine Station in Pacific Grove. Stevenson (1964) also used drogues (tracked with transits) to aid in a study of the near shore circulation in the southern periphery of Monterey Bay. Caster [1969] and others have studied the effects of the Monterey Canyon upon circulation utilizing current meters. 16 III. PROJECT EQUIPMENT A. PARACHUTE DROGUE SYSTEM The drogues utilized in this study were similar in design to those described by Volkmann, Knauss and Vine [1956]. The drogue system was basically comprised of a standard circular aviator's parachute suspended as a sea anchor beneath a surface float. The float supported a mast upon which was mounted a radar reflector (Figure 4). The parachutes were obtained through the Naval Supply System as over-age surplus. The diameter of the parachute was 8.5 m, giving an 2 effective cross-section area of 56.3 m when completely deployed. Each parachute was shackled via a ten meter length of nylon line to the bottom of the buoy mast, which pierced the surface float. A swivel device was placed between the bitter end of the line and the parachute to counter twisting of the shroud lines. A dead weight 60 lb (weight ^'n water) anchor was also suspended from the lower end of the line to keep the parachute properly deployed at depth and to keep the mast in an upright position. The surface float was composed of a .76 m x .61 m x .25 m section of styrofoam sandwiched by metal packing straps between two sheets of plywood. It was felt that a styrofoam float would be more durable than the often used inner tubes [Jennings and Schwartzlose 1960, Reid 1962 et al], which are subject to puncture and abrasion. The mast consisted of a five meter length of 6.35 cm diameter alumi- num piping (.16 cm wall thickness) internally reinforced by 6.1 cm diameter wooden doweling. The mast penetrated through the styrofoam 17 ALUMINUM CORNER REFLECTOR NAVIGATION LIGHT 5 METER ALUMINUM MAST STYROFOAM SURFACE FLOAT 10 METER NYLON LINE PARACHUTE DROGUE WITH SWIVEL DEVICE 60 POUND ANCHOR Figure 4. Parachute Drogue Assembly 18 float with four meters of mast remaining above the water line (Figure 5). The mast was color-coded for easy identification, and it was equipped with a navigation warning light. The radar reflector, used to increase the echo strength of the buoy, was secured to the top of the mast. Several radar reflectors were tested for this study. A spherical reflector (ECCO Reflector, model 2B-105) supplied by the Naval Oceanographic Office gave excellent near shore performance, but was severely range-limited (maximum range approxi- mately 15,500 m) (Figure 6). A fabricated aluminum corner reflector gave much better results, increasing range coverage out to approximately 28,000 m under ideal sea and weather conditions. The fundamental property of corner reflectors is that, within certain limits of inclination, a ray entering the corner will be reflected back specularly in exactly the opposite direction. The reflector used was actually an octahedral cluster of corner reflectors, designed to ensure equally strong echo returns from all sides of the buoy to compensate for drogue movement (Figure 7). The aluminum framework of the reflector was heavily perforated to cut down on wind resistance. The shipboard launchings of the drogue system were accomplished successfully by first jettisoning the parachute (Figure 8). As the parachute opened, the buoy and the weight were placed overboard (Figure 9). Only one drogue did not properly deploy out of the total of 39 drogues launched. B. AN/SPS-10E RADAR SYSTEM The primary tracking radar used in this study was the AN/SPS-10E radar system. The radar was designed primarily for shipboard use in the 19 Figure 5. Mast Configuration 20 Figure 6. ECCO Radar Reflector Figure 7. Octahedral Cluster Reflector 21 Figure 8. Jettisoning Parachute Drogue Figure 9. Launching Surface Float Assembly 22 detection, ranging and tracking of surface targets, and to a lesser extent low flying aircraft. This equipment is installed in many types of American and foreign vessels, including auxiliaries and men-of-war. The Naval Postgraduate School has a number of search and fire- control radars installed on the roof of a five-story academic building to serve as educational aids for the School's Electrical Engineering Department. The platform for the AN/SPS-10E radar antenna is located approximately 36.6 m above ground level and affords coverage of most of Monterey Bay (Figure 10). This search-type radar is omni -directional , thus permitting continual tracking of multiple targets. It operates in the "S" frequency band at 5450-5825 MHz. A summary of the radar's specifications is given in Table I. The maximum range for this radar for surface targets is gener- ally somewhat greater than the optical horizon as viewed from the radar antenna (The optical horizon in miles equals 1.22 times the square root of the antinna height; in this case 13.4 miles or 22.4 km). The strength of the returning echo though normally depends upon the size and shape of the target, its distance and height, its reflecting qualities, sea and weather conditions, antenna height and pulse length. Long pulse (1.3 microseconds) gives greater range than does short pulse (.25 micro- seconds). The long pulse length was used in this study. The radar presentation is shown on the PPI (plan position indicator) of the AN/SPA-25 radar repeater, which gives a 360 degree sweep coverage. From this presentation it is possible to obtain target position with a range resolution (long pulse) of 251.5 m and bearing resolution of less than one degree. A typical radar presentation for minimum sea return conditions (sea state 1) is shown in Figure 11. The range scale for this presentation is 50,000 yards (45,700 m). 23 Figure 10. AN/SPS-10 Radar Antenna 24 Figure 11. PPI Radar Presentation 25 TABLE I SUMMARY OF AN/SPS-10 SPECIFICATIONS FREQUENCY BAND: 5450 to 5825 MHz TYPE OF FREQUENCY CONTROL: Amplitude modulated TYPE OF EMISSION: Radar pulse (0.25 or 1 .3 microseconds) PEAK POWER OUTPUT: 190 kW to 285 kW PULSE RATE: Radar: 625 to 650 Hz Beacon: 312 to 325 Hz TYPE OF RECEIVER: Superheterodyne BANDWIDTH: Narrow band: 1 MHz Wide band: 5 MHz RADAR RESOLUTION: Bearing: Less than 1 degree Range, short pulse: 45.7 m Range, long pulse: 251.5 m C. MK 25 MOD 3 RADAR SYSTEM The MK 25 MOD 3 system is a conventional gunfire control radar used on naval vessels in conjunction with the Gunfire Control System MK 37 (Figure 12). It is a pulse-echo type of radar and operates in the "X" frequency band. This radar was used in the latter stages of the study because of its compatability with the AN/DPN-78, a radar transponder which had been acquired to increase the echo strength of the parachute drogue system. A disadvantage of this type of radar is that it cannot track multiple targets. It will lock on and track a single target, though, in an automatic mode. This greatly eases the tracking burden of the radar operator. 26 Figure 12. MK 25 Radar Antenna 27 D. AN/DPN-78 RADAR TRANSPONDER Several AN/DPN-78 radar transponders v/ere obtained for this study from the Naval Air Systems Command in order to amplify the echo strengths of the drogue buoys. This equipment is normally used in missile, satellite, target drone and aircraft applications as an enhancement device for "X" band tracking radars. Because of the availability of the MK 25 MOD 3 radar system at the Postgraduate School, it was felt that these transponders could be utilized as an aid in tracking the drogue buoys . A radar transponder receives interrogations within its specified operation band and then transmits replies back to the radar receiver on a different frequency within the same band. As a result, the operating range of the radar system is greatly extended over that given by a passive reflector. The AN/DPN-78 is an "X" band transponder which receives pulses in the 9100 MHz to 9600 MHz range (Figure 13). It transmits a reply pulse within the same range but offset from the radar receiver frequency by at least 50 MHz. The characteristics of the transponder are listed in Table II. 28 Figure 13. AN/DPN-78 Transponder and Antenna 29 TABLE II AN/DPN-78 CHARACTERISTICS RECEIVER: Frequency (tunable range) 9100 to 9600 MHz Type Superheterodyne Sensitivity (99% reply) -65 dBm over entire frequency range Bandwidth (3 dB) 8 MHz minimum Interrogation code Single or double pulse Pulse width 0.2 to 0.6 microseconds TRANSMITTER: Frequency (tunable range) 9100 to 9600 MHz Type Magnetron Peak, power output 200 W Pulse width 0.25 ± 0.1 microseconds Pulse repetition frequency 0 to 2000 PPS SIZE 8.53 x 7.37 x 10.06 cm VOLUME 619.9 cu cm POWER SOURCE '28 V CURRENT DRAIN 2.1 A 30 IV. PROJECT OPERATION In order to determine the feasibility of tracking drogues with the installed radar systems at the Naval Postgraduate School, and secondly to gather current data for circulation analysis, a tracking program was set up over a four month span from August to November 1971. During this period, 38 parachute drogues were released and tracked (Table III). The drogues were seeded by both the USNS DE STEIGUER and the School's oceanographic research vessel. The AN/SPS-10E surface search radar was utilized throughout this segment of the study in order to simultaneously track a number of drogues. It soon became apparent that the tracking system had several limi- tations. Under ideal sea and weather conditions (state 1 sea, wind force 0-1, unrestricted visibility), the maximum tracking range was approximately 28,000 m. This limited the study area for normal conditions to south of the Monterey Canyon. An additional difficulty was encountered with the inexplainable sudden loss of radar contact with drogues, which, until that time, had been providing strong echoes. The latter difficulty was determined to be the result of radar inter- ference from several stands of tall trees on the Postgraduate School campus. These trees partially blocked radar coverage of the Bay, creating shadow zones (Figures 14-16 show a panoramic view of the Bay from the radar platform and the stands of trees in question). In order to more accurately fix these shadow zones, the School's research vessel ran a figure eight set of course legs crisscrossing the lower reaches of the Bay. The radar track provided a good indication of where the shadow 31 TABLE III DROGUE TRACK DATA DROGUE START TIME1 STOP TIME1 TRACK DURATION 1 121743 Aug. 131000 Aug. 16 hr. 17 min. 2 121930 Aug. 130935 Aug. 14 hr. 5 min. 3 - - - 4 130100 Aug. 131045 Aug. 9 hr. 45 min. 5 130200 Aug. 130935 Aug. 7 hr. 35 min. 6 182030 Aug. 191545 Aug. 19 hr. 15 min. 7 182100 Aug. 191545 Aug. 18 hr. 45 min. 8 182200 Aug. 190930 Aug. 11 hr. 30 min. 9 182215 Aug. 182230 Aug. - 15 min. 10 182230 Aug. 191545 Aug. 17 hr. 15 min. 11 182300 Aug. 190230 Aug. 3 hr. 30 min. 12 182330 Aug. 190900 Aug. 9 hr. 30 min. 13 190000 Aug. 190730 Aug. 7 hr. 30 min. 14 - 310830 Aug. 010915 Sept. 16 hr. 45 min. ]! Local times CAUSE-CEASE TRACK Lost contact - high sea return Lost contact - long range No contact - long range Stopped tracking Lost contact - high sea return Stopped tracking Stopped tracking Lost contact - long range Lost contact - shadow zone? Stopped tracking Lost contact - shadow zone? Lost contact - shadow zone? Lost contact - shadow zone? Lost contact - shadow zone Interrupted track 32 DROGUE START TIME STOP TIME TRACK DURATION CAUSE-CEASE TRACK 15 310845 Aug. 16 310900 Aug. 17 310930 Aug. 18 311000 Aug. 19 311045 Aug. 20 311100 Aug. 21 311130 Aug. 22 311230 Aug. 23 060845 Oct. 24 060900 Oct. 25 060915 Oct. 26 061000 Oct. 27 061015 Oct. 28 061115 Nov. 29 061130 Nov. 30 071800 Nov. 312100 Aug. 12 hr. 15 min. 310930 Aug. - 30 min. 010530 Sept. 20 hr. 010915 Sept. 23 hr. 15 min. 311330 Aug. 2 hr. 45 min. 311230 Aug. 1 hr. 30 min.3 010300 Sept. 8 hr. 010915 Sept. 20 hr. 45 min, 061830 Oct. 9 hr. 45 min. 061530 Oct. 6 hr. 30 min. 061530 Oct. 6 hr. 15 min, 061345 Oct. 3 hr. 45 min, 061430 Oct. 4 hr. 15 min. 080700 Nov. 43 hr. 45 min, 061745 Nov. 6 hr. 15 min 081700 Nov. 23 hr. Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos Stopped tracking Lost contact - unknown Lost contact - shadow zone? Lost contact - shadow zone? Stopped tracking Lost contact - broken mast? Lost contact - broken mast? Lost contact - broken mast? Lost contact - shadow zone? Lost contact - shadow zone? Lost contact - long range Lost contact - shadow zone Stopped tracking Interrupted track 33 DROGUE START TIME STOP TIME TRACK DURATION CAUSE-CEASE TRACK 31 32 33 34 35 36 37 38 "X" ny n II711 071830 Nov. 081700 Nov. 22 hr. 30 min. 071900 Nov. 072030 Nov. 1 hr. 30 min. 071930 Nov. 081700 Nov. 21 hr. 30 min. 101000 Nov. 101300 Nov. 3 hr. 130130 Nov. 130900 Nov. 7 hr. 30 min, 130145 Nov. 130830 Nov. 6 hr. 45 min, 130200 Nov. 130830 Nov. 6 hr. 30 min, 130200 Nov. 130800 Nov. 6 hr. 100800 Nov. 101600 Nov. 6 hr. 100800 Nov. 102030 Nov. 12 hr. 30 min, 101000 Nov. 102000 Nov. 10 hr. - Stopped tracking Lost contact - shadow zone? Stopped tracking Lost contact - behind Pt. Pinos Stopped tracking Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos Lost contact - behind Pt. Pinos 34 Figure 14. Panaromic View of Bay (009-041 degrees true) Figure 15. Panoramic View of Bay (355-015 degrees true) 35 Figure 16. Panoramic View of Bay (318-353 degrees true) 36 zones existed for the drogues (true bearing arcs of 349.5 to 353 and 000 to 007) (Figure 17). These shadow areas corresponded very well with the sudden losses of radar contact (and occasional sudden reappearances) with a number of drogues. Figures 19, 24, 31, 37, 49 and 50 display all 38 drogue tracks. The losses of contact with drogues 9, 11, 12, 13, 14, 20, 21, 26, 27, 29 and 32 can probably be attributed to these radar blackout areas. In an attempt to obtain complete coverage of the southern half of the Bay, and also to extend the tracking range to include the northern region of the Bay, radar transponders were utilized. The transponders were AN/DPN-78 models, "X" band instruments compatible with the MK 25 MOD 3 radar system. One of the transponders was placed on the stern of the research vessel with its antenna at a height of four meters above the water! ine to approximate the masthead height of the drogue buoy. Another figure eight run was made across the southern half of the Bay with both the AN/SPS-10 and the MK 25 radars simultaneously tracking the target (While the AN/SPS-10 actually tracked the boat, the MK 25, in beacon track mode, tracked only the transponder, i.e. the scope presentation displayed only the beacon return and not other surface contacts). Radar contact was again lost through the shadow zones by the surface search radar, but solid contact was maintained throughout the track by the fire control radar (Figure 18) . The research vessel next set a course for Santa Cruz, at the north end of the Bay, to test the range capabilities of the transponder. Strong contact was maintained the entire track, which was terminated off of Soquel Point at a range of 37,000 m. 37 I22< 50' 36° 40i Copy of C.SG.S. Map 5402 - 20 FATHOMS -50 - 100 500 -1000 Figure 17. Radar Shadow Zones 38 A* Figure 18. Transponder Track 39 V. ANALYSIS OF CURRENT DATA In conjunction with the feasibility study, the drogue track data, over the four month period, was collected and analyzed. There were 38 drogues seeded and tracked during this period, resulting in a total accumulated tracking time of approximately 437 hours. The mean length of time of each individual drogue track was 11.5 hours, with the longest track being approximately 44 hours, and the shortest track 15 minutes. Hourly drogue course and speed data, as extracted from the charts, is listed in Appendix A. To help in the analysis of the drogue data, hourly wind readings were obtained from the Pacific Gas and Electric Company's Moss Landing power plant (Appendix B). This data was not very satisfactory for accurately estimating the wind velocity at the drogue positions, as the power plant is almost 12 km from the center of the southern half of the Bay. Lacking in situ wind though, this data had to suffice, as these are the only hourly readings taken in the southern Bay area (excepting readings taken at the local airfields which are located well in from the coastline). Tidal data was obtained from the tidal gauge located in Monterey Harbor, supplemented by data from a similar instrument at Moss Landing (Appendix C). The following is a synopsis and analysis of each individual drogue track (drogue tracks and wind-tide-current correlation graphs accompany each synopsis) : August 12-13: Drogue #1 - This drogue was placed overboard eight kilometers northwest of Pt. Pinos. Its general track was east then south toward the lee of % 40 122* s'o' tAHT* Cftl/tT V.- Figure 19. Drogue Tracks 1 - 5 41 CO o OJ O- co OJ CO o I— <_> o J OJ o +-> r— rt3 r— o co^: S- 0CTl o 1 o i— QJ CO CO •o o=> •I — O h- rD < -o ^t- c: o°^ •i— 1 S 4-> OJ C o O) s- s_ o 13 o CJ . o =«= oj ~ ojcn O) r— rs en i— O O CO i_ OJ ID O CD rD < • °o ~, O , OJ OJ r— O) i_ c£) 3 >— en cr> co CD lo CO OJ I— O r— I (•J3y 3snv9 ivau BAoav) sihoibh ivau 42 the Monterey Peninsula. Contrary to expectations, higher current speeds appear to be at the tidal extremities. At the start of the track, the wind blew briskly from the west and could account for the drogue's initially rapid movement into the Bay. Later backing of the wind could be a cause for drogue deceleration. Drogue #2 - Drogue #2 was placed in the center of the Bay, above the axis of the Monterey Canyon, due west of Moss Landing. The drogue movement was to the west, with a turn to the south during the last few hours of the track. There appears to be alternating accelerations and decelera- tions during the tidal cycle, but again, seemingly out of phase. The wind, except for the middle of the track, generally was in opposition to drogue movement. The drogue's movement along the axis of the canyon might be significant. Drogue #3 - This drogue was placed in the north central region of the Bay and was beyond radar contact. Drogue #4 - Drogue #4 was placed in the center of the Bay just south of the Canyon. It moved quite slowly first to the southeast, and then reversed course toward the northeast. The reversal is shown to have occured during a flood period. The wind, being generally from the south, might have influenced this reversal. Drogue #5 - Seeded about four kilometers north-northwest of Pt. Pinos, this drogue moved in the same general direction as drogue #1. Neither the wind nor the tide appeared to have forced this movement. Discussion Drogues #1 - #5 - Possibly the movements of #1, #2, and #5 indicate a counterclockwise gyre generated by the southward flow of the 43 C/5 o to d) OJ Cl- in CM -O c •r- O 2 q: o I— a: ex: q: o UJ CM c r— o •r— +-> S- r— s- o CO 1— C_) O V) rD cu CD XJ UD ZD • 1 — O < ■ CO "O 1 — c «3- • f— o 3 1 EZ CM OJ O S- S- 3 C_) O O CM =tts o CM |->- CD cm cn =3 r— cn O 1— i- o oo Q CM ID o :z> • < i — oo CM i— CM ^~ CU S- L vo CD r* cr> -i — — r- 1— i 1 co cm -I I .— o CO (*J3cJ 39flV9 1VQI1 3A09V) S1H9I3H 1VGU 44 to 4-> -o a; a> o. 10 CM -o e •r- o J c£ o I— o UJ a: cc C_> t/1 a; o I— UJ on <- to 4-> -a ai QJ D. to *3- . CM a; S- s- 3 O u CM KO _J UJ »—i >- I— O (T3 o » S- cri o r— o CO o \- a> co -a o •i — VO CD h- O ZD i < -a c ro •r- ^r r- IS o 1 4-> C CD CM s- O s- 3 o o *3- o =*»= o CD cm r--. 3 CM CTi CD r— o s- h- Q O I/) CM =D CD • ZD CM < CM CO i— CM CD i — S- CD co —T— 1— IT) — r - r" CO CT> I CM 1 1 r— O (*d3cJ 39RV9 IVQIl 3A03V) S1H9I3H 1VQI1 45 V) +-> ■D T3 ■a E •i— I 4-> C a; s- i- o Lf> =tfc •— < >- r cn — r- CO -J 1- - j— CO ~1 r- C\J I— — » o CdHti 39flV9 1VQI1 3A03V) S1H9I3H 1VQU 46 California Current. Drogue #4 could lie in the semi -stagnant center of this gyre. It is also possible that the drogue #4 parachute became fouled and did not open. This generally leads though to a strong wind dependent movement, which was not observed in this case. August 18-19: Drogue #6 - This drogue was seeded in the same area as was drogue #1. The overall movement was to the southeast, but with a definite reaction toothe ebb and flow of the tides. The increase in wind speed toward the northeast and east, may have attributed to the generally increasing current speed near the end of the track. Drogue #7 - Drogue #7 moved generally in an opposite sense than did drogue #2 the previous week. Placed at the seaward end of the canyon axis, it moved north and then to the east toward Moss Landing. The characteristic effects of the tide upon currents appeared to show up here, i.e. minimum speeds at high/low water, maximum speeds midway be- tween the two extremes. The direction of drogue movement appeared roughly to correspond to that of the wind, but a share acceleration in the wind did not effect, at least immediately, the current speed. Drogue #8 - This drogue was placed in the center of the Bay just north of the Canyon axis. Its movement was generally north than east. Drogues #8 and #7 had similar tracks, and may have been part of a clockwise eddy. Drogue #9 - This drogue was initially held on the radar, but quickly vanished, probably in the western shadow zone (Figure 17). 47 122' 50< *JkHT% e*i/».r • — w_. HOWS Figure 24. Drogue tracks 6-13 48 in ■M "O CU CU c to CM . -a c •i- o s o <=^ +J ■a O) ai o. to +-> c cu i- s- 3 o ^J- . CM - c o •r— fO raj 5- S- O o cu i i c cu s- s_ Z3 C_> :tfc CU 3 CD O i. Q CM cu s_ en _i UJ t— I >- I— o — 7— CO — r — 1~ CX> LO ro CM r— (•J3cJ 39flV9 1VQI1 3A09V) S1H9I3H 1VQII 49 ' to «^- •o CD CM s- u u o o C o •1— -o i — T3 r— CD t *fr XL ' i— O o r>- O (Tv i — sC •r™ is cr> i CO .— _j o c CJ i_ S- . 3 o C_3 r^. =*ts «5T o u Z5 o en c\j r^. o o en s_ r— Q l— O <£> - —r- CX> — f" CO CO <£> LO CM (*J3cJ 39CIV9 IVQIi 3A02V) S1H9I3H 1V0I1 50 ■l-> "O 0> Ol Q. to CVJ . -o c s o o o I- o o LU to 4-> — "*t. "O • a> • c a> s- s- 13 O' o o •r— 4-> «3 'aj s- s- o o CO -a i +-> c cu s- S- 13 O 00 =*= a> rs en O s- o C\J - o cr> co r»» vd tn ro C\J r— (•J3H 39flV9 IVQIl 3A09V) SJLH9I3H 1VQU 51 Drogue #10 - Drogue #10 was inserted close to the initial location of drogue #4. Again there was very little overall translational movement. The drogue rotated clockwise in a spiral turn greater than 360 degrees. The winds seemed to have no effect on the drogue movement. The tidal influence was shown by the drogue's movement seaward during the ebb tide and back toward shore during the flood tide. Drogue #11 - The drogue was launched 7.3 km southwest of the Salinas River estuary. It had a very short track moving slowly to the south and southwest, and then reversing course to the northeast. This reversal corresponded roughly to the start of the flood (no graph was drawn due to a paucity of drogue course/speed data). Drogue #12 - Drogue #12 was placed about 2.6 km east of drogue #10. Their movements were quite similar, i.e. in a clockwise spiral. The tide was again the predominating force affecting the drogue track. The southerly winds showed little apparent effect on the drogue movement. Drogue #13 - Another clockwise movement was noted for this drogue, which was deployed about 2.5 km west of Elkhorn Slough. As with drogues #10 and #12, the drogue moved with the ebb and flow of the tide, and showed no obvious reaction to the winds. Contact with the drogue was lost as it drifted into the eastern shadow zone (Figure 17). Drogue tracks for #10 and #12 were terminated in a like manner. August 31 - September 1 : Drogue #14 - This drogue was seeded in the southern extremity of the Bay, four kilometers northeast of Pt. Pinos. The drogue moved to the 52 in on o \- o UJ > o o a: -o ai O.CM -o c •r- O 5 O I— -4-> J* -o • cu O) a. to CM +-> • c - h- o 1 CT» CO c o •r- 4-> <~o fO r^ r~ cu s- s- ^t o <— o CD CM -a r- o •i — r^ i— en i i — -a o c i— i— •i — co :d c o < CJ S- en s- ^~ 3 U3 o O o r— «3- =*= o CD 13 CD CM o o s- o Q r«- cri O i— • CD CO 1— CM oo cm rs a> CM O i_ rD 13 < CD •i — O CO Ll_ CM r- — I — U3 in < ^t —i — CM ( " J3M 39flV9 1VQI1 3A09V} S1H9I3H 1VQI1 53 in +■> "O 0) V) -o • CD <1> Q. V) C\J. 4-> • C C CD X- s- o CM =«= CD en o S- Q CVJ OJ s_ CD «=C -J Q c_> i— i >- l— o CO CT> VD LT> CO C\J i— ("J3y 39fW9 "1VQI1 3A08V) S1H9I3H 1VQI1 54 to 4-> -o 0) 0J Q-CNJ CO ~o c •i- o s to oc o I— c_> CO o t— c_> o <=> CO <1J . CNJ C • CNJ r- (•jay 39nv9 ivan 3Aoav) sihdihh ivau 55 south for about five hours, at which time radar contact was lost. Contact was regained ten hours later two kilometers away to the north- west. Another southerly track followed, indicating the drogue had spiral ed counterclockwise. The tide recorders for both Monterey and Moss Landing were inoperative on the first of September therefore the accompanying graph is of little use. Drogue #15 - This one was placed in the same relative area as drogue #5, i.e. several kilometers north of Pt. Pinos. Whereas #5 moved in toward Monterey Harbor, #15 tracked to the west-southwest until radar contact was lost behind Pt. Pinos. The wind had no obvious effect upon this movement, in fact it blew in the opposite direction for much of the track. The seaward movement might be explained by the sweep down the coast of the California Current. The current might branch off of Pt. Pinos, with the main flow continuing south along the coast (carrying with it drogue #15), and the branch going east into the Bay proper creating eddies. Drogue #16 - This drogue was planted about five kilometers northwest of Pt. Pinos and promptly tracked to the southwest behind the Point. Drogue #17 - Southerly movement was again noted with drogue #17, emplaced 9.4 km northwest of Pt. Pinos. The track moved behind the Point after making a short jog first to the east, and then back to the west. The movement toward the Bay occured during an ebb, therefore the tide does not appear to account for it. The wind was blowing quite strongly from the west at this time, therefore it may be responsible. The general movement to the south again might be attributed to the oceanic current influence. 56 122' 50* *A«/rm e*tn.r 8G.S. 402 HOMS to -a <*t UJ o I— o o UJ <=^ to -^ -o «a-. CU • CO c cu S- s_ 3 O J O .^ on csj CO c o +j 03 O) S- S- o cu -o I -o c I c cu S- CU CJ) O CM O) s- en Q O t— I >- I— o cri oo Lf) ro CVJ i— (•J3cJ 39flV9 1VQI1 BAOaV) S1H9I3H 1VQI1 58 CO a: o co a: o h- o -O 0) a; c\j a. to ■o c o en o C=> 10 -a «=*- 0) • a. 10 ■p • c 0) S- J- 3 O +J fO p— a> s- s- o -3- o C\J 3 1— o <£> h- lo r— oo p— ID =«= CO ■=*" rD co «=C 3 en r— o co s- CM o • CO O CO CD X- 3 CO CT> o •r— < —I Q O i— i >- r o — V cr. CO — T" «3- T — CO *t -a **• cu • f0 r— a> s- S- o o a> «* -o CNJ •r- I— | -a OJ c: OO •r— ^ 4-> o o £= oo r-^ CD cr> s- ^— s- 00 3 r- 1— o m ZD r^» o r— KD ZD =tfc r- < a) ^— =5 CO en «=t- o r— s- Q r\i r- • ^d" n o t— a> S- Z3 en oo •»■■ o u_ 4-> C CD S- i- O - t— — 1 — — i — 1 — 1 — i I — -1 o cr> 00 r^ U3 in «3- CO OJ r- (•J3b 3snv9 ivau 3Aoav) sihoibh ivau 60 Drogue #18 - This drogue, launched in the center of the southern half of the Bay, tracked initially to the southwest and then looped clockwise around to a southeasterly head. The loop can be attributed to the tidal cycle. The winds seem to have little bearing upon the track. Drogue #19 - It was placed in the water 17 km west of the Salinas River. Sketchy contact was maintained for several hours, during which it appeared to move toward the southeast. Drogue #20 - Drogue #20 was initially held by the radar about four kilo- meters east of drogue #19' s starting position. An hour and a half later radar contact was lost, probably as a result of movement into the western shadow zone. Drogue #21 - This drogue, with its initial position in line with #19 and #20 but farther east, moved in a clockwise spiral for about four hours before disappearing from the radar screen. It reappeared nine hours later, 2.6 km to the east, and then moved to the southwest. The initial spiral was probably caused by the flood tide (although the graph shows the shoreward flow and the flood tide a few hours out of phase), and aided by westerly winds. Drogue #22 - This was another interrupted track, with passage through the eastern shadow zone. The drogue was initially located just east of drogue #18's start point. As with #18 and #21, it moved in a tide- controlled clockwise rotation. Discussion Drogues #14 - #20 - On top of the local tidal eddies, it appeared as if the drogues (with the exception of #14) were generally moving clockwise around the interior of the southern end of the Bay. 61 to o on o (A +J -a o> J* ■O • CD CD a. to CM +-> • c CD s- s- 3 O J O 'cD s- s_ o o CD ■a C CD S- S- o CO CD cn o s_ Q co CD S_ - I— O T" CT> T" co — T— T — — r CO 1 1 C\J i— (*J3cl 390V9 1VQI1 3A0aV) S1H9I3H 1VQI1 62 a: o i- o <=> .*: -a ^j- Q. to CM c cu s- S- 3 O O c o •1— +■> fO r-™ k cu s- s- sr o CO o cu ■a CM •i — CM h- i ■a c: O •r— CM 3 o 4-> r^. C co en o CM s- r_ Q o . r— VO CO cu CO S- o =3 CT> Q O i— i >- I— O CT> 1 — -r— — r- T — T — CO -J » CM r— CO ('J3H 39DV9 TVail 3A0aV) S1H9I3H 1VQU 63 V) +J -D 0) O <=> on -a a; ai TC> cu s- «=i- s_ CM o <_> CD CM -a CM •i— \— i -o O c: CM • r— 3: O i co r^ -)-> c— en c: f— CD s- I— s- 3 i— =3 o CJ3 ZD CM 3 en CM o pa S- Q o r- • r^ CO CO cu o s- 3 C7> CM CU S- S- 3 O O _l LU - I— c_> — r co -I- -r— —r~ ro en vo LO CM (*J3H 39flV9 IVQU 3A09V) S1H9I3H 1VQI1 64 October 6: Drogues #23 - #27 - The tracks for these drogues all roughly paralleled each other, moving east to northeast and then turning toward the south. They were planted in a relatively small cluster in the south central area of the Bay. The tracks were all abruptly terminated as the result of mast buckling failures (see Chapter VI). The movements of the drogues were probably jointly the result of the strong southwesterly winds and the flooding tide. Additionally, the northward flowing Davidson Current, which occurs during this season of the year, could have been directing flow into the Bay, and possibly setting up a clock- wise gyre. November 6-8: Drogue #28 - The overall track of this drogue was steadily to the northwest from its initial position four kilometers north of Pt. Pinos. This tracking period was quite lengthy and exhibited a large variance in wind conditions. The winds in general did not seem to effect the track. There were no tidal loops, nor did the current speed vary directly with the ebb and flow of the tide. It would appear therefore, that the Davidson Current's northerly flow is the primary forcing mechanism in this case. Drogue #29 - This drogue moved for about six hours to the northeast before contact was lost in the western shadow zone. Its starting position was about eight kilometers north of Pt. Pinos. The movement into the Bay was probably the combined result of the prevailing winds and the flood 65 I£S< 50< l r-. Figure 38. Drogue Tracks 23 - 27 66 to cc o r- 4-> "O OJ 01 O-CM to ■o c •r- O o o UJ a: O a: o ai <=3 +-> -^ **- ■o a> a» o. CO c\i +j c a; s_ i~ o o c o •r" 4-> CO i— CD i- S- o o a> -o I -a CO c 1 — CL) t_ S- zs co c_> r- O r^. co CTl CM ^~ =*fc *3" r— CC a> UJ Z3 CO CXI O O c\j h- s_ i— C_3 Q O O CO • r— CT> CO CU CO S- o 3 CD ■=C —I Q O r— O — T- CT> — r~ co —J — —\ — CD —T— Lf> — » CM CO Cd3cJ 39fW9 "1VQU 3A09V) S1H9I3H 1VQU 67 to ■»-> «3- ■a CU cu CM Q. CO •i- o 2 CO o I— o CO o I— a: O or o a: <=> CO +-> •o • cu cu ex CO C\J 4-> • c a> i_ s- 3 O (J c o •r" -l-> »o ^— cu s- s- o o cu •o •1— 1— ■a c •1— 3 +J c cu co S- r— S- 3 c_> CD "**• r— C\J o =*fc r^ CX« cu «=*• i— 3 ■ — cr. or o lu s_ CO Q CSJ o 1— h- o • o o o ^t- i— CO a> S- 3 00 CD o •i— «=C _l Q O 1— CO — I CNJ cn CO CD LD (•J3H 39flV9 1VQI1 3A09V) S1H9I3H "lVQIi 68 in 4-> ^r ^£ -o 0) C\J c • i. i. o o CD T3 •r- »— i -o c •1— 3 00 i 1— +-> c O! s- s- i— o 3 r-» <_: en r— Lf> «vt* cv i— CC =*t LU CO a> C\J o 3 r— 1— C) O o o s- o c i— VD . r— CO «* O - I— O o -I — *3" — \ C\J — r- cn — j— 00 Id CO (*33cJ 39IW9 1VQU 3A03V) S1H9I3H 1VQU 69 +J "— "3- •o (U eu to CM -o c to a: o l- o C_) CO on o I— o UJ on o C£ <=J 4-> J* -O • H co 01 a. in CM c CD 5. S- 3 O O o •r- +J «3 'aj i. s- o o a> -a i -a c i E a> s_ s- zs C_> VO CM =«= cu 3 en o s- CNJ - I— O — T- CTl — T" -1 CM 00 UD to (*J3cJ 39flV9 IVQIl 3A09V) S1H9I3H 1VQI1 70 +-> -* **• -o ai ai CLCM V) IS) en o l— o •r- O en o I— o LU en en r> o en o en <: to +-> — «d- -o • • c s- S- 3 O •» O c o (0 'a; i. s_ o o a> -o i C CD a> tO s- r— s- o 3 r^ t_3 *3- en i— ~ i—- r-^ C\J en =tfc LU CM CQ O) r— O 3 h- CD o o o S- o a i— to co 00 <3- o a> s- cC —I Q O t— • >- I— O en CT> CO to CO CM (•J3cj 3snv9 ivau 3Aoav) S1H9I3H ivau 71 its1 Vo' kum cm/it HOMS Figure 44. Drogue Tracks 28 - 33 72 4-> ■D n3 O) S- s- o o CD I -o c CD s- s- O 00 CVJ O i- Q CD S- 3 CD cn CO — '^~ ■o • (U • c s- S- u o c o « a> s- i. o O GJ T3 1 ■a c c a s. s_ C_3 CJ =tte cu CD o i- o s- en — r — r" «3" - 1 F~ CVJ i— cy. co LO ro CJ3H 39AV9 IVQU 3A09V) S1H9I3H 1VQU 74 tide, with the possible additional impetus of a branch of the Davidson Current swinging into the Bay to form a clockwise gyre. Drogues #30 and #31 - These drogues generally followed the pattern exhibited by drogue #28, but appear to be somewhat more influenced by the tides. The winds, being quite variable over the time span, do not seem to play an important role in the drogue movement. Drogue #32 - During this drogue's very short track, it moved to the southeast from its position on the southern rim of the Canyon. Radar contact was lost when it drifted into the western shadow zone. Drogue #33 - Drogue #33, placed in the water about ten kilometers out the Canyon axis from Moss Landing, moved in a clockwise spiral out from its initial position. The floods and ebbs of the tidal cycle were probably the cause of this spiral, but the accompanying graph shows that they were out of phase with the drogue's movements. Again, maybe an offshoot of the Davidson Current controlled this track. November 10-13: Drogues #34 - #38 - All of these drogues, planted north and west of Pt. Pinos, rapidly moved behind Pt. Pinos on southwesterly courses. The tides appeared to have little influence upon the tracks. The wind for tracks #35 - #38, though, was blowing strongly out of the northeast, and probably affected the drogues significantly. This possibly was in conjunction with a movement of the California Current back in toward the coast over- powering the weakened Davidson Current. 75 .*£ — "tf- •o cu a> a. to C\J •o c •r- 5 O J a: o id 10 <3" •o • CD a; a. to CM ■i-> • c cu s- j_ 3 O U GO o i— o _ CO c o n3 cu i- j- o o cu -o I X) c: c a> s- 13 o o ro =«= cu o s- Q CU s- en (— c_> "T" — r~ ro i r cr> co C\J i— (*J3« 39HV9 IVQU 3A03V) S1H9I3H 1VQI1 76 CO CO TIDAL CYCLE 1 1 i i 1 1 1 1 CT> CO r-» ud LT> <3- CO C\J TO S- S- o o a; i +-> c: CD S- S- 3 cu zs en O l- Q CO C1J S- =3 cn (*J3>J 39RV9 1VQI1 3A09V) S1H3I3H "IVQI1 77 co 4-> -o 01 0) Q.CM CO ■o c •r- O s q: CO 4-> J*l '«* •o • cu a. CO C\J c a> u i. Z3 O o o •r™ -M (O O) S- s- o cu ■o I ■a i CO CO =tte cu CD o S- O cx> ^- cu S- en _J UJ - I— C_J - r — T CT> CO ^1- co C\J i— Cd3b 39HV9 1VQI1 3A03V) S1H9I3H 1VQI1 78 » 3604O* .8G.S. 402 H0M8 Figure 50. Drogue Tracks 34, "X", "Y", "Z" 79 Iff fa Figure 51. Drogue Tracks 35 - 38 80 to ■M -a a> dj CLCNJ to ■o c SO to a: o i— LU or a; r> c_> to or o h- o Q CC O LU or <=3 to JX ■D «* ai a. 00 C\J +-> • E O) S- i- 3 O O o oj £9 c\j O cvj «E o c\j CM c o as a; j- s- o c_> CD I -a c a> s- i_ O ro =«= O) 31 O o CvJ o LD r— cu s- CO 3 o Ol _J LU «=C — 1 a o •— i >- -T" Ol - r CO ~T" —f— CO LO CO (*J3b 39flV9 TVQIl 3A09V) S1H9I3H "Mill 81 to +J -a a> • c 01 i_ S- =3 o o CO" _l UJ - I— c_> 4-> 'aj s- i- o S- 73 en CO - r -J- in - 1- ro CO I cri 1^ 10 (•J3U 39HV9 IVail 3A00V) S1H9I3H 1VQI1 82 to +J •a a> 0) Q. to CNJ -a c •r- 20-1 co o O a: o a: o h- o LxJ a; <=3 ■a CD cu o_ CO CXI a; s- S- =5 O CJ s c o ■P" 4-> o i — *l — a cc: •o LU •r- CO (— CO s: 1 LU T3 > EZ o •r— s ^3 CO +J n $_ S- 13 o CO CO \ \ =tt I .* CD \ \ 3 \ w tT) O \A o 1 r* fi \ * • «=r j i \ LD cu 4 V $_ % Z3 *» 1* CD < —I o o •— I >- J— o u_ -r— en "I — CO - 1- -r~ CD -r- —I sl- (•J3« 39flV9 1VQI1 3A09V) S1H9I3H 1VQU 83 t/1 ■*■» J*. -a •**- J* • ■ t— i >- c 1— O 01 s- s- 3 o . o - r~ - 1 1 1 1 1 o <7\ 00 r-» <^> LO c o •I— 'aj s- s- o a; i c c J- i- 3 O CO =*: a> rs C") o Q m ID a) s.. 3 (•J3U 39nV9 IVQIl 3A03V) S1H9I3H "IVQU 84 to J* -** -o 01 •I CO- CO CM ■ •o c '5oj CO a: o en cc en <=3 to +-> 34 — -*d- -O • CD CD O- CO CM +J • c 01 S- s- 3 o o a: o h- o E O *rm 4-> •r- Vo 0 2: 3= 1 +-> CO c - \— O o CTv CO CO LO Cd3cl 39fW9 1VQI1 3A0aV) S1H9I3H 1VQI1 85 Drogues "X", "Y" and "Z" - These three drogues were picked up on radar on 10 November. They were three of the six drogues launched and tracked during the 6-8 November period. Their tracks closely resembled those of the #34 - #38 drogues. 86 to ■M J^. « •a a; a> a. CM. to •o c 3 a' o C_) a: en in o h- o UJ a: o LU cc: <: to J* cu • co Q. 00 CM 4-> • C CU S_ S- ZJ o o 'aj %- s_ o o a> -a i -o i jj Z5 C_3 CU CD O S- CD Q O l-H >- I— O "T- CD "T" CO to - r- IT) CO Cd3c] 39fW9 1VQI1 3A09V) S1H9I3H 1VQI1 87 43 -o O) CD Q- CM -o so - CO cc: o «— o ce: oo ce: o t— o o UJ cc: <: — *«* -o • O) CO Q- CVJ +J • c Q) i- S- 3 O O c o •r- +-> rO 'cj S- s- o o •1) -a I o iz 0) _ C7> o i- Q CO (X) CJ S- 13 CD < —I Q O i— I >- I— O ~i — CO » ('J3H 39nV9 1VQI1 3A09V) S1H9I3H 1VQI1 88 to o tO -^ *d- ■o 01 <1) Q. to C\J « TJ C •r— SO a: o h- o UJ a: a: a: o a: <: to 4-> • -a s. s- 3 O J U r 1 1 i 1 i 1 » 1 o tn 00 r^ ^J" CO c o •r— 4-> fC a> s- s- o o <3J I I +J E a> s_ s~ o M CD ZJ CT O S- Q tn a; a> Cd3b 39HV9 1VQI1 3A09V) S1H9I3H 1VQI1 89 VI. RESULTS AND CONCLUSIONS A. SYSTEM FEASIBILITY Although the feasibility study was not fully completed, i.e. transponder-equipped drogues were not seeded and tracked, it is felt that the success of the AN/SPS-10 radar system in tracking the drogues (equipped with corner reflectors) and the successful testing of the AN/DPN-78 transponder combined to make the system a viable method for use in the study of the surface circulation in the entire Bay. The parachute drogue system performed satisfactorily throughout the study. It proved to be a durable system, performing well in winds up to 22 knots, and in estimated state 3-4 seas. The only buoy failures occurred during'the October study period. Buoys 23, 24 and 25 had mast buckling failures under force four winds (13-16 knots). These failures were caused by a lack of internal reinforcement for the masts, which was the result of an unavailability of wooden doweling at the time. The final disposition on the 35 other drogues was: nine drogues drifted outside radar contact behind Point Pinos; radar contact was lost with four drogues due to long range; ten drogues were lost when they drifted into shadow zones; two drogues were lost when high sea return precluded maintenance of radar contact; six drogue tracks were terminated due to operator fatigue; and one drogue was lost for no known reason (It was tracking at a medium range outside of shadow zone areas when lost.). The MK 25 MOD 3 and the AN/SPS-10E radar systems both showed the capability of tracking drogues under moderate sea and weather conditions throughout the Bay. The fire control radar, when operated with an "X" 90 band radar transponder, gave full coverage of the Bay (Although the transponder was not mounted on a buoy, the placement of one aboard the research vessel with its antenna at the normal buoy masthead height, indicated this capability). The surface search radar was both range- limited (approximately 28,000 m) and hindered by shadow zones when operated with the passive corner reflector, but (noting its range capa- bilities), if it is utilized in conjunction with a "C" band transponder, it will give full coverage of the Bay alsc. The SPS-10 PPI presentation was generally excellent throughout the tracking periods, although there were sea and weather limitations. The minimum tracking range was about 2500 m. The antenna's angle of depres- sion at close range, looking seaward from the roof of Spanagel Hall, is such that an extreme amount of sea return blanks out the target area. As the sea conditions worsen, this minimum detection range increases. Several drogues were lost during this study because of high sea return. Heavy storm clouds can also affect the presentation. On one occasion several hours of track were lost due to cloud interference. An error study was made on the accuracy of the surface search radar. Over a twelve hour period, bearing and range to two fixed buoys were taken at half hour intervals and then compared with the charted positions. The results are shown in Appendix D. The bearing accuracy was excellent. The maximum error was one degree, and the mean error about 0.3 degree. The specifications for the radar give the bearing resolution as less than one degree. The maximum range error was 320 m with the mean range error about 295 m. The radar specifications give long pulse range resolution as 251.5 m. This accuracy is outstanding taking into effect: meandering 91 of buoy mooring; possible error in chart position of drogue; radar operator error; and lack of knowledge of exact charted position of the radar antenna (this was estimated). An error study was not made of the MK 25 radar because of its classification. One definite source of error not inherent in the system is the radar mounting. Usually in a shipboard installation the radar is mounted atop a MK 37 Gun Director. At the School, the radar is mounted on a pre-WW II 36" search light pedestal (Navy Type 36-20). In the electrical system involved with this configuration, there is a certain amount of error in the bearing accuracy. B. SURFACE CIRCULATION Monterey Bay, being a wide embayment open to the sea, must be considered to have a very complex surface circulation system. There are multiple driving mechanisms which can effect the circulation at any one time. These factors will vary hourly, diurnal ly and seasonally, with one mechanism at times dominating the others. In this study, 38 drogue tracks, compiled over a four month period, August - November 1970, were analyzed to glean the generalized current patterns at the time of the track study. The study was necessarily limited to the southern half of the Monterey Bay. The correlations of the drogue tracks to the winds, tides and oceanic currents was investigated, In general, the drogue tracks indicated that when the California Current moved near to the coast in the late summer and early fall, this oceanic current became a dominating current driving mechanism, particu- larly in the outer waters of the Bay. In the late fall, when the Davidson Current prevailed off the coast, it in turn, became a dominant 92 current driving mechanism. These two oceanic currents appeared to set up gyres within the Bay, clockwise for the Davidson Current and counter- clockwise for the California Current. Within the confines of the inner Bay, the effects of the tidal cycle were wery apparent. Local tidal eddies often were formed. Farther out in the Bay, the effects of the tide became less and less. In general, it appeared that the effects of the local winds were not too important in driving the currents. They did become important though, when the wind remained prevalent from a specific direction over an extended period of time. These conclusions can not be considered hard and fast, since they were based on analysis made over a relatively short period of time. As discussed in Chapter VII, it is recommended that a thorough drogue study be initiated over the time span of a full year to corroborate or refute these conclusions, and to analyze the conditions which exist during the upwelling season as well. 93 VII. RECOMMENDATIONS In that the Postgraduate School's radar installation has proven to be a useful tool, in conjunction with parachute drogues, to help study the surface circulation in the Bay, it is felt that further more detailed applications of this system should be employed. A long range study, planned over a period of a full year, should be initiated to witness the full effects of seasonal variations upon the surface current patterns. Each tracking interval should be at least 24 hours in duration in order to obtain the effects of the full tidal cycle. To fully employ the advantages given by the use of radar transponders, it is recommended that AN/DPN-77 units be utilized for this long range study. This transponder model operates in the "C" band, and thus is compatible with the AN/SPS-10E radar system. As a result, multiple transponder-equipped drogues could be tracked simultaneously. A synoptic analysis could therefore be made of the entire Bay. For a study of the surface circulation in a small area of the Bay, e.g. to study the current pattern in the area of a proposed sewage outfall, the MK 25 radar could be used with a single AN/DPN-78 equipped drogue. By integrating a simple X-Y plotter into the radar's tracking system, it would be possible to use the system's automatic tracking mode to alleviate the requirement for constant vigilance by a radar operator over an extended period of time. Any study utilizing transponder-equipped drogues will require close liaison with the School's research vessel. During the study just completed, 94 the drogues were considered expendable after the completion of each tracking period. Future studies though will require that the expensive transponder packages be retrieved after each tracking run. 95 APPENDIX A DROGUE COURSE/SPEED DATA TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #1 : 121800 Aug. 088 0.70 1900 046 0.70 2000 099 0.50 2100 112 0.40 2200 124 0.30 2300 114 0.25 130000 152 0.15 0100 144 0.25 0200 134 0.40 0300 166 0.34 0400 179 0.20 0500 187 0.10 0600 198 0.15 0700 218 0.10 0800 162 0.05 Drogue #2: 122000 Aug. 328 0.20 2100 285 0.30 2200 275 0.20 2300 267 0.10 130000 255 0.30 0100 255 0.20 0200 255 0.10 0300 298 0.25 0400 274 0.25 0500 272 0.20 0600 258 0.34 0700 237 0.05 • 0800 201 0.10 0900 167 0.20 Drogue #3: No track (never gained contact) Drogue #4: 130200 Aug. 143 0.15 0300 130 0.15 0400 156 0.10 0500 160 0.10 0600 182 0.15 0700 191 0.10 0800 026 0.10 0900 028 0.10 1000 030 0.15 96 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #5: 130200 Aug. 132 0.40 0300 169 0.40 0400 150 0.34 0500 168 0.20 0600 175 0.15 0700 135 0.15 0800 094 0.20 0900 097 0.20 Drogue #6: 182100 Aug. 112 0.25 2200 090 0.25 2300 124 0.20 190000 238 0.175 i 0100 221 0.20 0200 215 0.25 0300 120 0.075 0400 132 0.125 0500 043 0.10 0600 097 0.075 0700 065 0.025 0800 056 0.30 0900 069 0.225 1000 130 0.30 1100 134 0.25 1200 144 0.375 1300 143 0.20 1400 132 0.225 1500 133 0.275 Drogue #7: 182100 Aug. 017 0.225 2200 074 0.125 2300 334 0.20 190000 327 0.20 0100 342 0.30 0200 019 . 0.275 0300 031 0.40 0400 034 0.275 0500 034 0.20 0600 034 0.425 0700 069 0.50 0800 101 0.425 0900 107 0.50 1000 163 0.25 1100 200 0.225 1200 096 0.225 1300 081 0.15 1400 084 0.275 1500 143 0.20 97 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #8: 182200 2300 190000 0100 0200 0300 0400 0500 0600 0700 0800 Aug. 034 353 328 328 003 030 071 089 080 087 090 0.20 0.325 0.225 0.275 0.45 0.20 0.20 0.275 0.15 0.125 0.25 Drogue #9: 182215 Aug. Mo track (lost co ntact after 15 min.) Drogue #10: 182300 190000 0100 0200 0300 0400 0500 0600 0700 0800 0900 1000 1100 1200 1300 1400 Aug. 214 252 285 356 003 037 065 093 087 146 165 180 207 235 237 263 0.175 0.40 0.175 0.30 0.45 0.15 0.275 0.175 0.175 0.20 0.25 0.375 0.40 0.325 0.225 0.05 Drogue #11 : 182300 Aug. Very short track. Move >d due south 250 yds., 2300-2400. Shifted to approximate head 250 for 30 min. covering 200 yds. Reversed track to about 070 for 2 hrs. covering 400 yds. Lost contact at 190230 (shadow zone?). Drogue #12: 190000 Aug. 230 0100 229 0200 261 0300 293 0400 026 0500 056 0600 012 0700 064 0800 117 0.275 0.325 0.425 0.275 0.40 0.425 0.375 0.30 0.175 98 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #13: 190000 Aug. 355 0.125 0100 292 0.30 0200 305 0.075 0300 272 0.05 0400 028 0.075 0500 055 0.125 0600 016 0.175 0700 068 0.325 Drogue #14: 310900 Aug. 209 0.10 1000 193 0.275 1100 204 0.20 1200 197 0.20 1300 193 0.175 4 010100 Sept. 193 0.075 0200 184 0.10 0300 195 0.10 0400 207 0.10 0500 207 0.075 0600 192 0.075 0700 162 0.05 0800 132 0.225 0900 184 0.25 Drogue #15: 310900 Aug. 225 0.325 1000 219 0.30 1100 266 0.375 1200 258 0.225 1300 264 0.15 1400 273 0.30 1500 277 0.25 1600 305 0.125 1700 302 0.125 1800 298 0.175 1900 277 0.34 2000 290 0.10 Drogue #16: Tracked to the southwest for 30 min. Lost contact - behind Pt. Pinos. 4 Interrupted track 99 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #17: 311000 Aug. 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 010000 Sept. 0100 0200 0300 0400 0500 Drogue #18: 311100 Aug. 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 010000 Sept. 0100 0200 0300 0400 0500 0600 0700 0800 Drogue #19: Tracked to the southeast for several hours. Lost contact (reason unknown). Drogue #20: No track (lost contact after 1 1/2 hours - minimal movement). 211 0.275 193 0.125 130 0.075 085 0.075 130 0.25 134 0.20 151 0.225 155 0.25 216 0.20 287 0.175 222 0.20 219 0.15 248 0.225 251 0.15 235 0.10 222 0.10 199 0.125 209 0.20 196 0.25 201 0.275 246 0.325 252 0.275 323 0.175 041 0.125 072 0.225 116 0.225 078 0.30 109 0.15 120 0.25 125 0.25 103 0.30 133 0.275 106 0.225 152 . 0.15 188 0.05 188 0.05 165 Negligible 165 Negligible 165 Negligible 165 Negligible 135 0.05 132 0.10 100 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #21 : 311200 Aug. 323 0.2 1300 357 0.2 1400 056 0.34 1500 058 "?:_3 5 010000 Sept. 207 0.125 0100 220 0.125 0200 213 0.15 Drogue #22: 311300 Aug. 278 0.275 1400 322 0.25 1500 020 0.375 1600 060 0.34 1700 101 0.3755 2100 080 0.375 2200 082 0.25 2300 083 0.10 010000 Sept. 206 0.15 0100 202 0.175 0200 170 0.15 0300 183 0.15 0400 195 0.125 0500 195 0.10 0600 195 0.125 0700 218 0.225 0800 219 0.175 Drogue #23: 060900 Oct. 068 0.60 1000 057 0.50 1100 061 0.45 1200 081 0.375 1300 084 0.40 1400 093 0.30 1500 121 0.225 1600 118 0.325 1700 193 0.20 Drogue #24: 061000 Oct. 060 0.525 1100 055 0.50 1200 055 0.30 1300 055 0.25 1400 077 0.225 1500 114 0.175 5 Interrupted track 101 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #25: 061000 Oct. 052 0.65 1100 055 0.25 1200 055 0.075 1300 055 0.075 1400 350 0.15 1500 043 0.30 Drogue #26: 061100 Oct. 025 0.375 1200 050 0.325 1300 003 0.05 Drogue #27: 061100 Oct. 001 0.50 1200 019 0.40 1300 052 0.425 1400 106 0.30 Drogue #28: 061300 Nov. 310 0.275 1400 310 0.125 1500 290 0.20 1600 311 0.20 1700 327 0.20 1800 327 0.10 1900 281 0.10 2000 257 0.05 2100 257 0.05 2200 244 0.25 2300 246 0.175 070000 248 0.325 0100 253 0.425 0200 283 0.333 0300 280 0.325 0400 273 0.375 0500 298 0.40 0600 315 0.375 0700 327 0.40 0800 330 0.475 0900 352 0.55 1000 348 0.45 1100 338 0.325 1200 342 0.30 1300 336 0.325 1400 327 0.325 1500 342 0.34 1600 342 0.275 1700 336 0.125 1800 277 0.10 1900 250 0.05 2000 248 0.10 2100 247 0.15 2200 247 0.15 2300 247 0.275 102 TIME APPR0X. COURSE APPROX. SPEED(kts) Drogue #28 (cont'd) 080000 276 0.225 0100 290 0.30 0200 275 0.325 0300 292 0.30 0400 314 0.425 0500 316 0.34 0600 304 0.40 Drogue #29: 061200 Nov. 048 0.175 1300 048 0.175 1400 051 0.20 1500 040 0.15 1600 056 0.25 1700 082 0.25 Drogue #30: 071800 Nov. 268 0.25 1900 263 0.175 2000 244 0.15 2100 183 0.20 ' 2200 207 0.125 2300 241 0.225 080000 249 0.30 0100 248 0.275 0200 258 0.325 0300 253 0.30 0400 263 0.275 0500 311 0.25 0600 302 0.225 0700 345 0.325 0800 352 0.30 0900 358 0.325 1000 002 0.325 1100 002 0.325 1200 348 0.175 1300 310 • 0.10 1400 276 0.10 1500 264 0.15 1600 244 0.275 Drogue #31 : 071900 Nov. 293 0.10 2000 278 0.05 2100 278 0.05 2200 259 0.225 2300 251 0.175 080000 260 0.40 0100 290 0.30 0200 272 0.45 0300 303 0.375 0400 294 0.325 103 TIME APPROX. COURSE APPROX. SPEED(kts) Drogue #31 (cont ■d) 080500 319 0.225 0600 339 0.65 0700 002 0.325 0800 010 0.34 0900 021 0.475 1000 046 0.40 1100 031 0.25 1200 009 0.175 1300 333 0.05 1400 333 0.10 1500 338 0.10 1600 338 0.125 Drogue #32: Very sh ort track. Moved for 1 1/2 hours on approximate headi ng 170 covering 550 yds. Lost contact (sha dow zone?) . Drogue #33: 072000 Nov. 095 0.175 2100 117 0.20 2200 152 0.15 2300 229 0.325 080000 234 0.275 0100 237 0.34 0200 253 0.30 0300 284 0.175 0400 325 0.275 0500 344 0.225 0600 359 0.10 0700 012 0.375 0800 030 0.225 0900 048 0.40 1000 051 0.325 1100 043 0.275 1200 021 0.10 1300 041 0.125 1400 054 0.275 1500 267 0.15 Drogue #34: 101000 Nov. 246 0.34 1100 233 0.45 " 1200 238 0.375 1300 226 0.40 Drogue "X": 100800 Nov. 240 0.25 0900 234 0.34 1000 231 0.20 1100 232 0.375 1200 236 0.45 1300 224 0.34 104 TIME APPR0X. COURSE APPROX. SPEED(kts) Drogue "Y" : 100900 Nov. 190 0.15 1000 164 0.20 1100 118 0.125 1200 166 03 1600 236 0.40 1700 232 0.425 1800 229 0.475 1900 232 0.425 2000 236 0.475 Drogue "Z": 101100 Nov. 137 0.40 1200 151 03 1600 192 0.34 1700 195 0.325 1800 210 0.45 1900 219 0.375 2000 203 0.45 Drogue #35: 130200 Nov. 180 0.325 0300 164 0.425 0400 182 0.34 0500 191 0.375 0600 201 0.575 0700 223 0.575 0800 231 0.575 Drogue #36: 130300 Nov. 210 0.45 0400 213 0.45 0500 205 0.475 0600 229 0.70 0700 241 0.65 • 0800 230 0.675 Drogue #37: 130300 Nov. 162 0.225 0400 180 0.325 0500 205 0.375 0600 214 0.45 0700 212 0.50 . 0800 214 0.475 Drogue #38: 130500 Nov. 219 0.275 0600 225 0.45 0700 228 0.525 'interrupted track 105 APPENDIX B WIND DATA Pacific Gas & Electric Co., Moss Landing August: 121700 - 260/10kts 311100 - . 262/05 1800 - 262/09 1200 - . 269/07 1900 - 250/10 1300 - ■ 256/07 2000 - 239/09 1400 - ■ 271/11 2100 - 214/09 1500 - ■ 241/11 2200 - 189/08 1600 - ■ 224/12 2300 - 166/03 1700 - ■ 219/14 130000 - 167/02 1800 • ■ 208/16 0100 - 165/01 1900 - ■ 191/16 0200 - 164/01 2000 • ■ 168/11 0300 - 158/02 2100 • ■ 161/13 0400 - 161/02 2200 • ■ 159/05 0500 - 167/01 2300 ■ ■ 171/03 0600 - 159/02 0700 - 148/03 September: 0800 - 164/01 0900 - 187/05 010000 - ■ 129/03 1000 - 199/05 0100 - ■ 146/03 1100 - 249/03 0200 • ■ 281/02 182100 - 246/06 0300 • ■ 158/02 2200 - 233/05 0400 - ■ 203/02 2300 - 210/05 0500 • • 155/02 190000 - 200/05 0600 ■ ■ 131/03 0100 - 188/06 0700 ■ - 142/02 0200 - 176/05 0800 • ■ 133/02 0300 - 177/08 0900 ■ - 137/04 0400 - 177/07 1000 ■ ■ 187/05 0500 - 176/03 0600 - 172/02 October: 0700 - 172/05 0800 - 204/11 060800 • ■ 271/06 0900 - 208/11 0900 ■ ■ 236/06 1000 - 225/08 1000 ■ ■ 249/03 1100 - 252/07 1100 • - 228/06 -1200 - 253/07 1200 ■ - 248/09 1300 - 233/08 1300 ■ ■ 254/10 1400 - 261/09 1400 • ■ 245/12 1500 - 265/11 1500 • - 232/14 1600 - 261/12 1600 ■ - 231/15 310800 - 169/03 1700 ■ - 235/14 0900 - 149/02 1800 ■ - 232/16 1000 - 228/03 1900 ■ ■ 250/05 106 November: 061100 - 144/13 081000 - 132/04 1200 - 156/10 1100 - 133/02 1300 - 201/13 1200 - 274/02 1400 - 221/20 1300 - 314/02 1500 - 214/22 1400 - 298/03 1600 - 219/21 1500 - 302/05 1700 - 220/19 1600 - 271/03 1800 - 234/16 1700 - 265/04 1900 - 231/17 1800 - 273/01 2000 - 229/15 100800 - 182/01 2100 - 259/09 0900 - 148/01 2200 - 301/06 1000 - 173/01 2300 - 251/05 1100 - 295/03 070000 - 212/03 1200 - 305/05 0100 - 295/02 1300 - 302/07 0200 - 130/01 1400 - 301/08 0300 - 109/04 1500 - 296/12 0400 - 118/07 1600 - 304/10 0500 - 115/09 1700 - 304/07 0600 - 118/07 1800 - 292/05 0700 - 124/11 1900 - 293/05 0800 - 123/12 2000 - 282/03 0900 - 126/06 2100 - Calm 1000 - 124/06 130100 - 074/04 1100 - 132/04 0200 - 089/05 1200 - 256/05 0300 - 094/07 1300 - 263/08 0400 - 082/11 1400 - 261/06 0500 - 083/19 1500 - 263/06 0600 - 079/15 1600 - 269/08 0700 - 074/15 1700 - 270/07 0800 - 082/13 1800 - 274/03 0900 - 076/14 1900 - 266/02 2000 - 224/01 2100 - 225/04 2200 - 134/01 2300 - 087/03 080000 - 138/01 0100 - Calm 0200 - 203/01 0300 - Calm - 0400 - 089/03 0500 - 108/02 0600 - 122/04 0700 - 117/08 0800 - 118/07 0900 - 114/04 107 APPENDIX C MONTEREY HARBOR TIDE READINGS TIME HT. ABOVE TIDAL TIME HT. ABOVE TIDAL GAUGE REF. GAUGE REF". 121700 Aug. 8.5 312100 Aug. 8.0 1800 8.8 2200 8.2 1900 8.9 2300 7.9 2000 8.5 010000- 0700 Sept, , No reading 2100 7.9 0800 5.72 2200 7.85 0900 6.69 2300 5.6 1000 7.25 130000 4.45 0100 3.5 060800 Oct. 6.56 0200 3.0 0900 6.68 0300 2.9 1000 6.94 0400 3.3 1100 7.25 0500 3.95 1200 7.62 0600 4.8 1300 7.75 0700 5.6 1400 8.25 0800 6.3 1500 8.2 0900 6.7 1600 7.88 1000 6.8 1700 7.2 1100 6.6 1800 1900 6.3 5.38 182000- 190800 Aug. ' inoperable 061100- 081400 /. Tide gauge inoperable 190900 Aug. 6.0 1000 7.2 081500 Nov. 5.9 1100 8.2 1600 6.68 1200 8.5 1700 7.3 1300 8.2 1400 7.4 100800 Nov. 8.6 1500 6.5 0900 7.5 1600 5.3 1000 1100 6.3 4.7 310800 Aug. 6.0 1200 3.55 0900 6.7 1300 3.2 1000 7.2 1400 3.3 1100 7.4 1500 4.0 1200 7.0 1600 4.9 1300 6.4 1700 6.3 1400 5.7 1800 7.2 1500 5.3 1900 7.5 1600 5.1 2000 7.5 1700 5.3 2100 6.9 1800 5.8 1900 6.6 130100 6.2 2000 7.5 1200 5.0 108 TIME HT. ABOVE TIDAL Nov. GAUGE REF. 130300 5.05 0400 5.9 0500 6.55 0600 7.3 0700 8.5 0800 9.2 0900 9.5 109 APPENDIX D Bearing/Range Accuracy Data (12 Hour Study-6 Oct) SPS-10 Radar Position Charted Position Time Buoy "D" Buoy "A" Buoy "D" Buoy "A" 009/15700 012.5/5850 0730 009/16000 012/6160 0800 008.8/15990 012.3/6200 0830 008.8/15950 012.1/6170 0900 009/15970 012.5/6180 0930 008.8/15980 012.5/6190 1000 008.8/15990 012.3/6180 1030 008.9/15950 012.5/6150 1100 009/15980 012.7/6190 1130 008.8/15980 012.5/6190 1200 009/15940 012.5/6170 1230 009/15920 012.8/6160 1300 009/15960 012.5/6180 1330 009/15970 012.5/6190 1400 009/15970 012.5/6200 1430 009/15950 012.5/6200 1500 009/15940 012.7/6200 1530 009/15950 012.5/6200 1600 009/15970 012.5/6200 1630 008.9/15980 012.5/6200 1700 008.5/15950 012.5/6160 1730 009/15940 012.5/6200 1800 009/15960 013.5/6200 1830 008.7/15960 012.5/6200 1900 009/16000 012.5/6200 no BIBLIOGRAPHY Bureau of Ships, Technical Manual for Radar Set AN/SPS-10, 4 May 1953. Bureau of Weapons, Ordnance Pamphlet 1845, Vol . 1 , Description, Instal- lation and Operation of Radar Equipment MK 25, MOD 3, 6 January 1960 Bureau of Yards and Docks Final Report on Contract No. 13116, Deter- mination of Wave, Surge, and Ship Motion,, U.S. Naval Station Long Beach, California, by R. T. Knapp, 36p., May 1951. Caster, W. A., Near Bottom Currents in Monterey Submarine Canyon, Unpubl i shed Master's Thesis, Naval Postgraduate School, 1969. Coast and Geodetic Survey, Tide Tables for West Coast of North and South America, 1970. Cromwell, T., Montgomery, R. and Stroup, E., "Equatorial Undercurrent in the Pacific Ocean Revealed by New Methods," Science, v. 119, p. 648-649, 1954. Jennings, F. D. and Schwartlose, R. A., "Measurements of the California Current in March 1968," Deep Sea Research, v. 7, p. 42-47, 1960. Naval Air Systems Command, Preliminary Technical Manual for Radar ipondei June 1969. inary DPN-7* Transponder AN/DPN-77 and AN/DPN-78 (NAVAIR 16-30 DPN77-1), 15 Neumann, G. and Williams, R. E., "Observations of the Equatorial Under- current in the Atlantic Ocean at 15 W During Equilant I," Journal of Geophysical Research, v. 70, p. 297-304, 1965. Reid, J., "Measurements of the California Countercurrent at a Depth of 250 Meters," Journal of Marine Research, v. 20, p. 134-137, 1962. Robson, R., "Radar Method in Ocean Current Detection," Commonwealth Engineer, v. 42, p. 219-225, January 1955. Skogsberg, T., "Hydrography of Monterey Bay, California. Thermal Conditions, 1929-1933," Transactions of the American Philosophical Society, v. 29, 1936. Stalcup, M. C. and Parker, C. E., "Drogue Measurements of Shallow Currents on the Equator in the Western Atlantic Ocean," Deep Sea Research, v. 12, p. 535-536, 1965. Stevenson, C. D., A Study of Currents in Southern Monterey Bay, Unpublished Master's Thesis, Naval Postgraduate Schoo'l , 1964. Ill Stommel , H., "Serial Observations of Drift Currents in the Central North Atlantic Ocean," Tellus, v. 6, p. 203-214, 1954. Thomson, C. W. and Murray, J., "Report on the Scientific Results of the Voyage of HMS Challenger," Narrative, 1885. Volkmann, G., Knauss, J. and Vine, A., "The Use of Parachute Drogues in the Measurement of Subsurface Ocean Currents," Transactions of the American Geophysical Union, v. 37, p. 573-577, 1956. Wooster, W. S. and Gilmartin, M., "The Peru-Chile Undercurrent," Journal of Marine Research, v. 19, p. 97-122, 1961. Wylie, F. J. (ed.), The Use of Radar at Sea, 4th ed., American Elsevier, 1968. 112 INITIAL DISTRIBUTION LIST No. Copies 1. Defense Documentation Center 2 Cameron Station Alexandria, Virginia 22314 2. Library, Code 0212 2 Naval Postgraduate School Monterey, California 93940 3. Professor Warren W. Denner J Department of Oceanography Naval Postgraduate School Monterey, California 93940 4. Professor Edward B. Thornton 1 Department of Oceanography Naval Postgraduate School Monterey, California 93940 5. LCDR Howard Sanford Stoddard 1 175 Ridge Road Nutley, New Jersey 07110 6. Department of Oceanography 3 Naval Postgraduate School Monterey, California 93940 7. Mr. M. J. Dole, Jr. 1 Department of Engineering Research Pacific Gas and Electric Company 4245 Hollies Street Emeryville, California 94608 113 Security Classification DOCUMENT CONTROL DATA -R&D (Security classihc alion of title, body ot abstract and indexing annotation nust be entered when the overall report is classified) 1 originating activity (Corporate author) Naval Postgraduate School Monterey, California 93940 2a. REPORT SECURITY CLASSIFICATION Unclassified 26. GROUP 3 REPOR T TITLE Feasibility Study on the Utilization of Parachute Drogues and Shore-based Radar to Investigate Surface Circulation in Monterey Bay 4 DESCRIPTIVE NOTES (Type ot report and.inctusive dates) Master's Thesis; March 1971 5 au THORiSi (First name, midde initial, last name) Howard Sanford Stoddard 6 REPOR T D A TE March 1971 7«. TOTAL NO. OF PAGES 115 76. NO. OF RE FS 19 •a. CONTRACT OR GRANT NO. 6. PROJEC T NO. 9a. ORIGINATOR'S REPORT NUMBER(S) S6. OTHER REPORT NO(S) (Any other numbers that may be aasi/tned this report) 10 DISTRIBUTION STATEMENT Approved for public release; distribution unlimited II. SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIVITY Naval Postgraduate School Monterey, California 93940 13. ABSTRACT An intensive study is presently being made of the current patterns in Monterey Bay. Up to this time, no means has been available to examine the flow over the entire Bay. The feasibility of utilizing radar systems installed at the Naval Postgraduate School to track free-floating parachute drogues was investigated. Radar transponders extended the tracking range of the radars to include the north end of the Bay, and eliminated shadow zones which had been present when tracking passive reflectors. An analysis of the drogue tracks indicated the importance of the oceanic currents as primary current driving mechanisms. Tides strongly influenced flow in the Bay's interior. Winds generally were a relatively unimportant driving mechanism, except when winds prevailed from one direction over an extended period of time. DD,Fr..1473 S/N 0101 -807-681 1 (PAGE 1 ) 114 Security Classification A-S1408 Security Classification key wo R DS Parachute Drogues Circulation in Monterey Bay Monterey Bay DD,Fr."..1473 'back S/N 0101-807-6821 115 Security Classification A- 3 1 409 Crawford — — SHELF BINDER ^^^m, Syracuse, N. Y, ; Stockton, Colif. ^esis 126613 S734 Stoddard c.l Feasibility study on the utilization of para- chute drogues and shore- based radar to investi- gate surface circulation in Monterey Bay. 19 APR73 2 FCQ70 6 oA/< 87 >0 JAN *7 21878 Thesis 126 513 S734 Stoddard c."1 Feas'bMity stu^v on the utilization of para- chute drogues and shore- based radar to investi- gate surface circulation in Monterey Bay. thesS734 Feasibility study on the utilization of 3 2768 002 02026 5 DUDLEY KNOX LIBRARY